An essential quality of color is temperature. Temperature can be used to attain a color balance. Temperature can be used to enhance spatial relationships within an image. Temperature can be used to elicit psychological responses within the viewer. Understanding and exploring the dynamics of temperature in color can benefit any visual artist.

There are physical characteristics of color linked to temperature. The color temperature of light (Kelvin degrees) is determined by measuring a black body radiator (an object heated so that it emits light). As the physical temperature of the object rises, color transitions from red (long wavelengths – low energy) to blue (short wavelengths – high energy) through ROYGBIV (red, orange, yellow, green, blue, indigo, violet). When it comes to light sources, physically, blue is warmer than red.

There are also psychological qualities of color linked to temperature. Psychologically, blue is cooler than red. These associative qualities of color with regard to temperature are almost universally accepted. This is due in large part to our physical environment – water is blue, plants are green, sunshine is yellow, fire is red.

Using the qualities of one sense (touch) to describe the qualities of another (sight) can be a tenuous affair and may lead to ambiguity and confusion. The more precise a language is the more useful it is. The language of HSL (hue, saturation, luminosity) is a very precise language. When using the language of HSL, hue values mark a position measured in degrees on a color wheel. A circle has 360 degrees, so the scale is 0 – 359.

While every degree represents a new hue, you can use broader terms to describe a color family; red, orange, yellow, etc. Think of the color wheel as a clock where every hour marks a new color family.

0 red

30 orange

60 yellow

90 yellow green

120 green

150 blue green

180 cyan

210 green blue

240 blue

270 purple

300 magenta

330 blue red

Absolutely warm and cool colors can be found at 0 (red – the warmest color) and 180 (cyan – the coolest color) degrees. Determining whether one color is warmer or cooler than another can be measured by their proximities to these poles. A line between 90 (green yellow) and 270 degrees can be used to broadly demarcate warm colors from cool colors; colors on the right (towards red) are warm while colors on the left (towards cyan) are cool. The association of yellow with the sun, a warm light source, subtly skews the associative quality of warmth towards yellow (60) and away from blue; as a result, colors above the line between 0 and 180 tend to seem warmer than colors below it. (i.e. while both are equally distant from red (0), orange (30) seems warmer than blue red (330).) While one color can be seen as warmer or cooler than another color, each color also has warm and cool components; there are warm yellows and cool yellows, warm blues and cool blues, etc. (Where numerical classifications of colors define hues very specifically (1 degree per hue, 30 degree spread per linguistic color), linguistic specifications of colors (red, orange, yellow, etc) define broad ranges of hues.) Defining the warm and cool endpoints of any linguistic color is useful at a coarse level of granularity but becomes increasingly subjective at a fine degree of granularity. At what point does blue become purple? At what point does blue become green?

It’s possible to describe the adjustment of hue simply in terms of warming and cooling.

Photographic color adjustment strategies rely on adjusting a balance in each of three complements.

Red – Cyan

Green – Magenta

Blue – Yellow

Most hue adjustment tools, like Photoshop’s Color Balance, have these complements built into their interface. You can’t increase one hue without decreasing its complement.

Each set of complements has a warm and cool dynamic.

R (warm) – C (cool)

G (cool) – M (warm)

B (cool) – Y (warm)

These three complementary axes have different warm/cool dynamics with respect to the three color primaries – RGB.

red (warm red) – cyan (cool blue) warm/cool

green (cool green) – magenta (cool red) cool/cool

blue (warm blue) – yellow (warm green) warm/warm

You can analyze the color temperature dynamics at work in any image by sampling it and graphing it. Doing this will not only help you understand how it works but also how you might improve it.

You can make a field of color appear more dynamic, complex, and three-dimensional by preserving or introducing a variety of warm and cool components in it.

The temperature of color carries spatial associations with it. Warm colors tend to appear to be nearer than cool colors. Again this is universal. It can be overturned by many factors; some factors are related to color, such saturated colors appear nearer than desaturated colors or a progression from light to dark may be the primary element that establishes spatial hierarchy; some factors are not related to color, for instance, placement and overlap in composition may be primary spatially, overriding color relationships.

Color balance, spatial proximity, association – these are just three of the uses of warm and cool color dynamics in images. Whether you are adjusting preexisting color relationships or creating new ones, having thoroughly explored the warm and cool dynamics of hue, you can apply that knowledge towards the realization and enhancement of your images.

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To better see color within an image it can help to abstract it. By de-emphasizing an image’s representational qualities you can more easily direct your attention to the color relationships within it. In short, you can see them better because you’re not distracted by other concerns.

Using Photoshop, there are many ways to modify an image in order to better reveal it’s color structure.

You can blur an image. Blurring an image reduces detail so that you can more easily see the basic composition and the color relationships within it, without getting hung up on the details. (Duplicate the background layer and apply the filter Gaussian Blur.)

Blur an image substantially and you can reduce an image to a field of color. Compositional elements are significantly downplayed, leaving pure color. (Duplicate the background layer and apply the filter Gaussian Blur with a stronger setting.)

Pixellate an image and you can reduce an image to blocks of color. Composition is eliminated whilecontrast between colors is more pronounced than in a flat field of color. (Try Filter: Pixellate: Mosaic. This works best for lower resolution files or copies of files.)

Average an image and you can reduce all the colors in an image to one. (Duplicate the Background Layer and apply the filter Average – found under Blur.) This often confirms the dominant color in a composition. Well balanced color photographs containing a variety of hues tend to average towards gray.)

While accents and other important colors can also be used, the dominant color is an excellent choice to further analyze color relationships in an image using Blend Modes. With this technique you can see the variety found in the separate components of color within an image – Luminosity, Saturation, Color, and Hue. (Change the Blend Mode of the averaged layer to the desired color component.)

With a Blend Mode of Hue, all values in an image will be driven to the same hue. This will help you see variety in luminosity and saturation more clearly.

With a Blend Mode of Saturation, all values in an image will be driven to the same saturation. This will help you see variety in luminosity and hue more clearly.

With a Blend Mode of Color, all values in an image will be driven to the same hue and saturation. This will help you see variety in luminosity (the tonal structure) more clearly. (This variant is often the most useful as it is the easiest to interpret. With repeated analysis of many different images, you’re likely to note that images with less variety in hue and saturation (particularly neutral ones) will require more luminosity contrast to have an impact. By the same token, images with a great deal of variety in hue and saturation will often appear overly harsh with excessive contrast.)

With a Blend Mode of Luminosity, all values in an image will be driven to the same luminosity. You’ll eliminate contrasts in value which will help you see variety in hue and saturation more clearly.

This type of analysis will better reveal the color relationships at work within an image. You can use the information you’ve gathered by analyzing color relationships in an image not only to better understand it but also to make predictions about how you might improve them.

Increasing contrast in one or more of the elements of color (hue, saturation, luminosity) will increase separation in a composition; conversely, decreasing contrast will create greater unity.

Typically, well-structured images use a large amount of contrast in one color component, a medium amount of contrast in a second component, and a small amount of contrast in a third component.

Graphing color can help you identify colors more specifically and understand relationships between color better. One way to graph color is to use the Color Sampler Tool in Photoshop in combination with the Apple color picker.

Using The Apple Color Picker

To access the Apple color picker choose Photoshop: General Preferences and change Color Picker from Adobe to Apple and click OK. To see the new the color picker click on Set Foreground Color or Set BackgroundColor icon in the Tool bar.

Unlike the Adobe color picker, the Apple color picker is a color wheel. Creating and using color wheels to describe color and plot color relationships is a time honored tradition dating back to Leonardo DaVinci. Some of the most famous color wheels were created by Newton, Goethe, and Munsell. The Apple color picker is an additive color wheel where complements are defined as red and cyan, green and magenta, and blue and yellow.

You can sample any color in an image and find its position on the Apple color wheel.Using the Eyedropper Tool, sample a color in a composition. Then click on the Set Foreground Color icon. The Apple color wheel will appear and a small circle will plot the sampled color. You can make a record of this chart by taking a screenshot of the color wheel (caps lock, Shift, Command, 4). This will create a document on your desktop, which can be opened in Photoshop.

Combining Multiple Samples

You can combine multiple sample points into a single chart by taking multiple screenshots, opening them in Photoshop, and combining them. Drag the Background layer from one document into another and give it a meaningful title.Make sure the two layers are registered with one another. Then, mask off everything on the top layer except the circle identifying the color on the color wheel, the triangle identifying its luminosity on the slider to the right of the color wheel, and a portion of the color bar above the color wheel. You’ve just graphed the two colors on the Apple color wheel. You can do this with as many colors as you desire.

Once colors have been graphed you will be able to identify a variety of relationships between colors, both colors that exist in a composition and colors that do not.

Sidebar For Luminosity

You can identify luminosity values with the slider to the right of the wheel. By sampling colors from an image and noting their position on the slider you can determine whether an image is light (high key), medium, or dark (low key) and whether it contains low, medium, or high contrast, bycomparing thedistance between sampled points (the greater the distance the greater the contrast).

Lines For Differences In Hue

You can draw a straight and/or a curved line between two hues. This will help identify all the other hues between the two, useful in creating gradations or smoother transitions between two colors.

Concentric Circles For Saturation

You can draw concentric circles with varying radii on the wheel. This will help define the saturation level of an image – neutral, semi-neutral, saturated, or supersaturated.

Triangles For Color Families

You can divide the color wheel into triangular slices of varying widths. This will help define hue relationships within an image – monochromatic (single family hues)(within 30 degrees), analogous (closely related hues)(within 60 degrees), complementary (opposite hues)(separated by 180 degrees), or split complementary colors (three colors where two are found between 150 – 210 degrees from the third).

Shapes Show Relationships

You can draw geometric shapes inside the color wheel – triangles, squares, rectangles, pentagons, hexagons, octagons. This will help identify hues that may be used to create a logical color structure – diads, triads, quadrads, etc.

A little exploration and mapping of color will help you make many new discoveries about the color dynamics in any image, both of how they work and how they can be improved.

Revealing Relationships

Here are a few observations about the color dynamic revealed by graphing it.

1 The composition has four significant colors.

2 The luminosity has only moderate contrast, constrained to the mid-tones, weighted low.

3 The palette is reasonably saturated, but not supersaturated. The most saturated hue is dark purple, the second most saturated color is pink.

4 A 60 degree slice reveals that there are two reds and two purples – analogous (closely related) hues. The brown is actually a dark red with relatively low saturation. The reds are closely related in hue; so are the purples. There is a light set and a dark set of reds and purples. The hues are at the boundaries of analogous relationships, providing maximum variety within that color dynamic. Contrast is derived based on luminosity first, hue second, and saturation third.

5 While one hue, red, is the warmest color, the other hue, purple, lies close to the boundary between warm and cool colors. There isn’t a strong contrast between warm and cool, but there is a great deal of variety within a predominantly warm composition.

6 Gradation (smooth transitions) can be accentuated by including hues in between the sampled points either along a straight or curved line. The background color for the sky seems continuous and smooth because it contains many small steps between the lighter hue at the top and the darker hue at the bottom; this has a calm effect. The pink accents in the highlights appear warmer and lighter because they are surrounded by cool dark colors, without substantial gradation between them; this has an energetic effect.

One of the most distinctive features of a visual artist’s use of color is their use of saturation.

Many photographers are often asked, “Are you a black and white or color photographer?” (Curiously other visual artist’s are rarely asked this question.) While many people who ask it don’t mean it to be, it’s a loaded question. There’s often a latent assumption that you can’t do both well. In fact, work with one can strengthen work with another. Moreover, the question suggests that black and white (and shades of gray) are not colors, when in fact they are very specific colors – neutral colors. And, the question does not address with any specificity how a photographer uses more saturated color. Curiously, this question is rarely asked of painters and filmmakers. A more useful question might be, “How saturated is your palette?”

Neutral colors are characterized by a lack of saturation. Neutral lie along the luminosity spine that unites all hues. (Equal parts of complementary colors mix to create neutral colors.) At any one luminosity value there is only one truly neutral color. Using neutrals is comparatively simple, as two other variables (hue and saturation) in color are reduced to the same values (zero); it’s an economy of means. To appear luminous neutral images typically employ significant contrast in luminosity to compensate for it’s lack of hue and saturation. With a few exceptions, neutral images generally present a radical transformation of the way we see. Many people associate it with dream states, whether they dream in black and white or not. It is often thought of as elegant, if not conservative and restrained. The luminosity component of color aids in judging levels of illumination, spatial relationships, and volume. Formal qualities and qualities of illumination become a particularly significant concern in neutral images. Neutral images are often associated with antiquity or of timelessness.

A semi-neutral colors contain trace amounts of saturation. Values cluster around the luminosity spine within a small radius. Semi-neutrals do not include truly neutral colors. Semi-neutrals function very similarly to neutrals with additional complexity. Spatial relationships may be subtly accentuated by the slight addition of hue. Iridescent and lustrous color effects can also be achieved.

Images with reduced saturation use low levels of saturation. Values cluster around the luminosity spine within a larger radius but do not achieve full naturalistic saturation. Though not fully presented, the hue of elements within a composition becomes apparent. Similarly the ambient color temperature can be suggested. Spatial relationships can be more clearly delineated through hue. Hue becomes a significant concern in compositions, though it may or may not be a primary concern, depending on how it’s deliberate reduction is handled. Images with reduced saturation often do not appear realistic. They appear somewhat restrained, limnal, neither here nor there, but somewhere in between. Many people associate reduced saturation with the past, particularly the recent past.

Fully saturated images are the most representational images. Color can be used to make elements in a composition seem similar or different depending on the degree of contrast of one or more of its elements – hue, saturation, or brightness. All three elements of color can be used to describe qualities of form, space, and light. Often, to preserve a realistic appearance, luminosity contrast is lower than in neutral and semi-neutral palettes. Fully saturated palettes are relatively energetic. They have decidedly contemporary connotations.

Highly saturated images use a generous amount of saturation, without becoming unrealistically saturated. Hue becomes a dominant preoccupation. It may vie for becoming the primary focus of attention with subject, spatial relationships, or qualities of light. Highly saturated images are energetic. They have contemporary, generally expressive, and sometimes youthful connotations.

Super-saturated images use extreme levels of saturation. Realistic representation is generally not a concern. Colors often appear unrealistic. Additionally there is a tendency for colors to posterize, with abrupt transitions between different hues. Hue becomes the dominant concern, over subject or spatial relationships. Super-saturated images tend towards flatness. They are highly energetic, expressive, and sometimes associated with altered states of consciousness.

You can use the Color Sampler Tool in Photoshop in combination with the Apple color picker to graph color and identify the level of saturation of one or more images, either yours or someone else’s. See (list url for graphing color article) to find out how.

To lend unity to images within a single body of work it can be helpful, and in some cases necessary, to limit your use of saturation. Many artists will use just one level of saturation. While it is extremely difficult to present a wide array of saturation levels within a single body of work (though not a single image), for instance both neutral and saturated images, it is possible to present images that employ more than one level of saturation if they are closely related, such as reduced saturation and fully saturated or fully saturated and highly saturated palettes. As variety in saturation level rises it becomes more difficult to have separate images be seen as related.

When you think of Ansel Adams’ photographs you think of neutral images rather than highly saturated ones. When you think of Matisse’s paintings you think of supersaturated images rather than neutral ones. Think of your use of saturation as an essential component to defining your own signature style.